OAKLAND, Calif. -- After erasing what once appeared to be an insurmountable deficit, it has come down to this for the Oakland Athletics -- one game against the Texas Rangers to decide the American League West title.

Travis Blackley allowed one run over six innings in a strong bounce-back performance that helped the A's move into a first-place tie with Texas by beating the Rangers 3-1 on Tuesday night.

"As long as we believe inside this clubhouse and we know we can get it (done), we're going to do it. I honestly believe we're going to win tomorrow," closer Grant Balfour said. "Nothing is guaranteed, but it's about as good as. I believe we can go out and get it done."

And who would doubt these rag-tag A's after the remarkable run they have had to get to this point?

A night after holding a raucous celebration for clinching their first playoff berth since 2006, the A's erased the last piece of what had been a 13-game deficit in the division race on June 30 to take a share of first place for the first time since March 29.

Blackley (6-4) gave up three hits and struck out five a week after the Rangers knocked him out with a five-run first inning in the shortest start of his career. He allowed only an RBI double to Josh Hamilton in his longest outing since July 24, just the latest surprising performance in an improbable season for the low-budget A's.

"I just went out there like I had nothing to lose, and it worked out," Blackley said.

Derek Norris gave Oakland the lead in the fifth with an RBI single that scored a second run when right fielder Nelson Cruz bobbled the ball in right field for an error. Jonny Gomes added a solo homer in the sixth, and the bullpen did the rest in Oakland's fifth straight win.

Sean Doolittle and Ryan Cook each pitched a scoreless inning, and Balfour worked a perfect ninth for his 24th save in 26 chances. Balfour has three saves and a win in the past four days.

The A's will try to cap the comeback Wednesday in game No. 162 when A.J. Griffin (7-1) takes the mound against Ryan Dempster (7-3). Only four teams have won a division or pennant after trailing by at least 13 games.

"No one said it was going to be easy," Texas manager Ron Washington said. "We started out to play 162 games and now -- tomorrow -- it's 162. And we'll see what happens. We take it no different than we have been approaching it. We just haven't put our game together yet. Tomorrow we have to put it together. If we don't put it together, we still go to the playoffs."

The loser will go to the postseason as one of the two AL wild-card teams, needing to win a one-game playoff with Baltimore or the New York Yankees on Friday to advance to the division series.

"This isn't Game 7 of the World Series. It's not win or go home," Gomes said. "We're going to play loose. We're going to have fun and just continue to pass the torch. Hopefully tomorrow we get our pitching, defense and homers. That's been it for us."

The Rangers, who had held sole possession of the AL West lead since April 9, never expected to be in that position. But now they need one more victory to win their third straight division title.

They had been counting on Matt Harrison (18-11) to wrap up the title but now need to survive one more storm Wednesday to do it.

Harrison had been cruising along, retiring 10 straight batters before running into trouble in the fifth. Josh Donaldson led off with a single and advanced to third on Brandon Moss' double. Norris then lined a single to right field that scored Donaldson with the tying run. Third-base coach Mike Gallego initially held up Moss, but Cruz bobbled the ball for an error that allowed Moss to score.

Oakland tacked on an insurance run when Gomes hit his 18th homer with two outs in the sixth to make it 3-1, delighting the crowd of 30,660.

"He got two pitches up where he probably didn't want them," Washington said. "The one to Donaldson and the other to Moss. They were able to put something together in that inning and put some runs on the board. He fell behind on Gomes and he had to come in with a fastball strike, and Gomes didn't miss it. There's the score right there. We put just one run on the board tonight."

Game notes
The A's estimated a walk-up crowd of 12,000. ... The game-time temperature of 87 degrees was the warmest of the year in Oakland. ... The other teams to come back from at least 13 games down were the 1914 Boston Braves, the '51 New York Giants, the '78 Yankees and the '95 Seattle Mariners. ... Oakland reliever Pat Neshek will miss the final two games for the birth of his first child. ... Texas RHP Mike Adams rejoined the team after receiving a cortisone injection in his strained neck Monday. It is unknown when he will be able to pitch again.